Conventional sonar systems traditionally consist of a plurality of discrete transducers aligned in linear or planar arrays. Directional resolution is accomplished through analog or digital electronics by beam steering. Such systems usually require a large number of discrete transducers and electronics which includes signal conditioning amplifiers and digital computers. These are complex systems which are large, heavy, difficult to maintain and calibrate, expensive, and require significant electrical power.
One recent approach proposes an alternative means for obtaining high resolution without steering using derivative matched spatially shaded sensing apertures consisting of a number of discrete sensors. However, this implementation introduces directional ambiguities and/or implicit bandwidth limitations to prevent spatial aliasing. In addition, a large number of discrete sensors is required which continues the problem of large size, weight, expense, maintenance and calibration.